Father in law has then on this Road King......sounds like a thunder header but in stereo
I think they sound great in person, I ran a thunderheader on my last build, 2:1 with a falsee. Personally like the sound of the true dual setup a little better, has a little more "uniform" sound to it and can still wake the dead when you want to
As for looks, well, looks like a thunderheader X2 LOL not the most attractive exhaust on the planet, but it's accepted because of what it/they are.
If you like the thunderheader sound, no doubt you'll like the thundercones with a true dual header
We picked his set up on CraigsList for $250, there's a few used sets out there if you keep your eyes peeled in the usual places